NavList:

Frank, you wrote "Our lines of position are crossing with an angular separation of about 1°41' (roughly) which implies an error ellipse pointing nearly due north with a length in the north/south direction that is about 70 times greater than the east-west width. There's a much greater uncertainty in latitude than in longitude."

Using two horizontal angles, the "cut" angle of the two circles of position becomes 66°, indicating that this method is superior compared with the use of two transits, in this particular example. That is not always the case. If the three buildings have been lying on or close to the perimeter of a common circle, horizontal angles are useless.

Lars